brew something up
1. Lit. to brew something, as in making coffee or tea. Can somebody brew some coffee up? Let me brew up a pot of tea, and then we'll talk.
2. Fig. to cause something to happen; to foment something. I could see that they were brewing some kind of trouble up. Don't brew up any trouble!
brew up
Fig. to build up; [for something] to begin to build and grow. (Typically said of a storm.) A bad storm is brewing up in the west. Something serious is brewing up in the western sky.